There are several types of safety intravenous catheter designs. Most of the designs are similar to syringes or blood sampling devices that are available today. One such design is shown in a patent issued to JAGGER et al on Jun. 3, 1986 U.S. Pat. No. 4,592,744. This is a safety blood sampling device however it requires two (2) hands to operate or to cover the needle cannula.
Blood samples are also taken with syringes and there are also many safety syringes available. Some of these designs have a sleeve or sheath that will cover the needle after it has been used. Some typical designs with sleeves or sheaths are Z. M. ROEHR et al U.S. Pat. No. 3,008,570, Z. M. ROEHR U.S. Pat. No. 3,107,785, BARTNER, et al U.S. Pat. No. 3,895,633, G. K. BURKE U.S. Pat. No. 3,306,291, GYURE et al U.S. Pat. No. 4,300,678, WINSTEAD HALL U.S. Pat. No. 4,356,822, SAMPSON U.S. Pat. No. 4,425,120, LARSON U.S. Pat. No. 4,639,249, HARBAUGH U.S. Pat. No. 4,655,751, STRAUSS U.S. Pat. No. 4,664,654, BRAGINETZ U.S. Pat. No. 466,435, SPENCER U.S. Pat. No. 4,702,738, MILORAD U.S. Pat. No. 4,702,739, SPENCER U.S. Pat. No. 4,801,295, PONCY U.S. Pat. No. 4,816,022, and HUGHES U.S. Pat. No. 4,840,619.
Other designs have a retractable needle such as WELTMAN U.S. Pat. No. 3,306,290, and DENT U.S. Pat. No. 4,392,859. These designs do not have a means whereby the needle is extended from the syringe and held in place in a positive and rigid position in order to first inject the needle prior to injecting the medication. Still other designs have methods of bending to render the needle harmless after the medication has been injected. Most of these designs have one major purpose and that is to prevent the spread of infectious diseases such as aids, hepatitis, or other diseases from an accidental injection with a contaminated needle into others after the needle of the syringe was inserted into a patient with the above mentioned disease. These various designs all work well to a degree, but they all fall short of their intended purpose during the act of covering the needle, or removing the needle, which requires two hands.
Other devices such as TSAO U.S. Pat. No. 5,019,044, TSAO U.S. Pat. No. 5,084,018, SHAW U.S. Pat. No. 5,267,961, SHAW U.S. Pat. No. 5,120,310, DYSARZ U.S. Pat. No. 4,978,343 and DYSARZ U.S. Pat. No. 4,973,316 are all capable of releasing the needle if the container that they are packed in are dropped or jarred severly.
These devices do not have a protective latching means but they rely on friction to restrain the needle with a biased spring.